This invention relates to a double station machining vise having a stationary jaw positioned between two movable jaws, and which can be operated selectively to secure workpieces against either or both sides of the stationary jaw. Even more particularly this invention is related to a machining vice having two movable jaws which are hydraulically operable selectively to secure the different workpieces against opposite sides of a stationary jaw, or one workpiece against one side of the stationary jaw.
Heretofore it has been commonplace to employ a machining vise having positioned centrally on the frame thereof a stationary jaw positioned between two jaws which are movably mounted on the frame selectively to secure a workpiece against one side or the other of the stationaryjaw. Typical such machining vises are disclosed in U.S. Pat. No. 6,017,026, U.S. Pat. Nos. 5,505,437, 5,921,534 and U.S. Pat. No. 5,458,321. While these prior art vises are similar in function, the means for actuating the movable jaws generally rely upon mechanical connections to effect movement of the movable jaws relative to the associated stationary jaw. Although the U.S. Pat. No. 6,017,026 discloses means for hydraulically operating a two station machining vise, the problem is that the system employs hydraulic means in combination with a rotary spline mechanism for manipulating the movable jaws. Basically the patent discloses a combined rotary screw drive and hydraulic system for operating a vise utilizing one or two movable jaws and one stationary jaw, and suggests that when two movable jaws are employed the same type of apparatus is employed for manipulating each of the two movable jaws. The result is that a two line hydraulic system must be employed for moving each movable jaw to and from work clamping positions.
It is an object of this invention, therefore, to provide an improved hydraulically operated two jaw machining vise in which each of the two movable jaws of the vise are manipulated by a single, hydraulically operated system.
Still another object of this invention is to provide an improved, hydraulically operated two jaw machining vise which is substantially more inexpensive and easier to operate than prior such machining vises.
More specifically it is an object of this invention to provide an improved two movable jaw machining vise having a single piston operating system for manipulating the slides which shift both movable jaws relative to a stationary jaw of the vise.
A still further object of this invention is to provide an improved, rather simplified mechanism for releasably securing the two movable jaws of a vise on their associated operating slides.
Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims, particularly when read in conjunction with the accompanying drawings.
The vise includes a housing having in its upper surface an elongate recess with a cover plate secured thereover. Secured on the cover plate medially of its ends is a stationary jaw, and mounted for limited sliding movement on the cover plate adjacent opposite ends thereof are two movable jaws. Mounted for limited sliding movement in the recess beneath the cover plate are front and rear slides, respectively, and each of which has thereon an integral knuckle which extends through a registering opening in the cover plate and is releasably secured to one of said movable jaws. Each knuckle has on one side thereof a pin having a flat surface engageable with a registering cam surface on the associated movable jaw, and has at its opposite side a spring-loaded, pivotal detent which is releasably engageable with another section of the associated movable jaw, thereby releasably to connect each such jaw to the associated slide.
To effect movement of the movable jaws toward and away from the fixed jaw, an elongate piston is mounted in the housing recess with one end of its rod or shank section secured to the rear slide, and projecting adjacent its opposite ends slidably in an axial bore in the front slide, and with the end of the piston remote from the rear slide having formed thereon an enlarged-diameter piston head which is mounted for limited axial movement in a counterbore formed in the end of the front slide remote from the rear slide. A hydraulic fluid supply duct is connected at one end to a blind bore formed coaxially through the piston head and part way into the piston rod, which has a reduced-diameter end portion thereof integral with one side of the piston head. The opposite side of the piston head is engaged by a compression spring which normally urges the piston head into ajaw opening position in which it is seated against the bottom of the counterbore in the front slide. To actuate the movable jaws, hydraulic fluid under pressure is fed through the supply duct and the bore in the piston head to the blind bore which extends into the piston rod. The reduced diameter portion of the piston shank, which is integral with the head of the piston, has therethrough a pair of diametrally opposed radial openings which enable fluid under pressure to enter the annular space surrounding the reduced-diameter piston rod so that the fluid under pressure engages the side of the piston head opposite to the side thereof engaged by the compression spring. This fluid under pressure moves the piston head in the front slide and against the resistance of the compression spring, at the same time shifting the attached rear slide, and hence the attached rear jaw, toward the stationaryjaw. When the compression spring prevents farther shifting of the piston head in the counterbore in the front slide, the fluid under pressure now in the space between the piston head and the bottom of the counterbore causes the front slide and its associated movable jaw to shift longitudinally relative to the piston head toward the stationary jaw and against the resistance of another set of compression springs.
When it is desired to permit the movable jaws to return to their open positions, the hydraulic fluid is permitted to return to the fluid supply thereby permitting the associated compression springs to return the front slide to its original position, after which the other compression spring engaged with the piston head forces the piston head back to its original position, thus opening both movable jaws.